Project Summary/Abstract: (30 lines maximum) The overall goal of this proposal is to develop genetic and pharmacological interventions that will delay the onset and progression of Alzheimer?s Disease (AD). AD and other Related Dementias (ADRD) affect well over 5 million people in the United States. By mid-century, these numbers are predicted to at least triple. Despite this, there are no effective treatments for these devastating illnesses. The onset and progression of AD has been linked to age-related changes in several critical physiological pathways including cellular and mitochondrial metabolism and genomic stability. We propose the age-related decline in the efficacy of these pathways promotes AD-related neurodegeneration and interventions which improve and stabilize physiological pathways leading to extension of healthy life span will delay the onset and progression of AD. In this proposal we will use the fly and mouse AD models in combination to determine whether potential genetic and pharmacological geroprotectors known to extend life span or health span in flies and mice, through an enhancement of the activity of cellular and mitochondrial metabolism or improvement in genomic stability, delay the onset and progression of neurodegeneration and other AD-related phenotypes in AD models in mice and flies. The goal of these studies is to identify new and novel genetic and pharmacological geroprotectors that can be translated for use in the treatment of AD. We will use specific molecular genetic and pharmacological interventions known to extend life span in flies or to extend health span in mice in the context of molecular genetic models of fly and mouse AD. The effect of each intervention will be evaluated in two different fly AD models (neuronal-specific expression of human A42 or human tau) and the 5XFAD mouse AD model. We will test the hypotheses that: (i) genetic interventions known to improve cellular and mitochondrial metabolism or genomic stability and to extend life span in flies or health span in mammals serve as geroprotectors that can delay the onset and progression of the neurodegeneration associated phenotypes in the fly and mouse models of AD and (ii) pharmacological interventions known to improve cellular and mitochondrial metabolism or genomic stability and extend life span in flies or health span in mammals can delay the onset and progression of the neurodegeneration associated phenotypes in the fly and mouse AD models. We will determine whether these interventions delay the onset and progression of a series of AD-related neurodegeneration phenotypes including: (i) decline in whole organismal health (life span in flies, frailty in mice); (ii) loss of neurobehavioral robustness or resilience (mobility and circadian rhythms in flies, a series of neurobehavioral tests in mice); (iii) microscopic histological examination of neurodegeneration in the brain and the retina of flies and gross and microscopic neuro-pathological examination of the relevant regions of the mouse brain; and (iv) molecular changes in mice.